#!/usr/bin/perl -w

#

# A script to generate optimized C blitters for Simple DirectMedia Layer

# http://www.libsdl.org/

use warnings;

use strict;

my %file;

# The formats potentially supported by this script:

# SDL_PIXELFORMAT_INDEX8

# SDL_PIXELFORMAT_RGB332

# SDL_PIXELFORMAT_RGB444

# SDL_PIXELFORMAT_RGB555

# SDL_PIXELFORMAT_ARGB4444

# SDL_PIXELFORMAT_ARGB1555

# SDL_PIXELFORMAT_RGB565

# SDL_PIXELFORMAT_RGB24

# SDL_PIXELFORMAT_BGR24

# SDL_PIXELFORMAT_RGB888

# SDL_PIXELFORMAT_BGR888

# SDL_PIXELFORMAT_ARGB8888

# SDL_PIXELFORMAT_RGBA8888

# SDL_PIXELFORMAT_ABGR8888

# SDL_PIXELFORMAT_BGRA8888

# SDL_PIXELFORMAT_ARGB2101010

# The formats we're actually creating blitters for:

my @src_formats = (

    "RGB888",

    "BGR888",

    "ARGB8888",

    "RGBA8888",

    "ABGR8888",

    "BGRA8888",

);

my @dst_formats = (

    "RGB888",

    "BGR888",

);

my %format_size = (

    "RGB888" => 4,

    "BGR888" => 4,

    "ARGB8888" => 4,

    "RGBA8888" => 4,

    "ABGR8888" => 4,

    "BGRA8888" => 4,

);

my %format_type = (

    "RGB888" => "Uint32",

    "BGR888" => "Uint32",

    "ARGB8888" => "Uint32",

    "RGBA8888" => "Uint32",

    "ABGR8888" => "Uint32",

    "BGRA8888" => "Uint32",

);

my %get_rgba_string = (

    "RGB888" => "_R = (Uint8)(_pixel >> 16); _G = (Uint8)(_pixel >> 8); _B = (Uint8)_pixel; _A = 0xFF;",

    "BGR888" => "_B = (Uint8)(_pixel >> 16); _G = (Uint8)(_pixel >> 8); _R = (Uint8)_pixel; _A = 0xFF;",

    "ARGB8888" => "_A = (Uint8)(_pixel >> 24); _R = (Uint8)(_pixel >> 16); _G = (Uint8)(_pixel >> 8); _B = (Uint8)_pixel;",

    "RGBA8888" => "_R = (Uint8)(_pixel >> 24); _G = (Uint8)(_pixel >> 16); _B = (Uint8)(_pixel >> 8); _A = (Uint8)_pixel;",

    "ABGR8888" => "_A = (Uint8)(_pixel >> 24); _B = (Uint8)(_pixel >> 16); _G = (Uint8)(_pixel >> 8); _R = (Uint8)_pixel;",

    "BGRA8888" => "_B = (Uint8)(_pixel >> 24); _G = (Uint8)(_pixel >> 16); _R = (Uint8)(_pixel >> 8); _A = (Uint8)_pixel;",

);

my %set_rgba_string = (

    "RGB888" => "_pixel = ((Uint32)_R << 16) | ((Uint32)_G << 8) | _B;",

    "BGR888" => "_pixel = ((Uint32)_B << 16) | ((Uint32)_G << 8) | _R;",

);

sub open_file {

    my $name = shift;

    open(FILE, ">$name.new") || die "Cant' open $name.new: $!";

    print FILE <<__EOF__;

/* DO NOT EDIT!  This file is generated by sdlgenblit.pl */

/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken\@libsdl.org

*/

#include "SDL_config.h"

/* *INDENT-OFF* */

__EOF__

}

sub close_file {

    my $name = shift;

    print FILE <<__EOF__;

/* *INDENT-ON* */

/* vi: set ts=4 sw=4 expandtab: */

__EOF__

    close FILE;

    if ( ! -f $name || system("cmp -s $name $name.new") != 0 ) {

        rename("$name.new", "$name");

    } else {

        unlink("$name.new");

    }

}

sub output_copydefs

{

    print FILE <<__EOF__;

extern SDL_BlitFuncEntry SDL_GeneratedBlitFuncTable[];

__EOF__

}

sub output_copyfuncname

{

    my $prefix = shift;

    my $src = shift;

    my $dst = shift;

    my $modulate = shift;

    my $blend = shift;

    my $scale = shift;

    my $args = shift;

    my $suffix = shift;

    print FILE "$prefix SDL_Blit_${src}_${dst}";

    if ( $modulate ) {

        print FILE "_Modulate";

    }

    if ( $blend ) {

        print FILE "_Blend";

    }

    if ( $scale ) {

        print FILE "_Scale";

    }

    if ( $args ) {

        print FILE "(SDL_BlitInfo *info)";

    }

    print FILE "$suffix";

}

sub get_rgba

{

    my $prefix = shift;

    my $format = shift;

    my $string = $get_rgba_string{$format};

    $string =~ s/_/$prefix/g;

    if ( $prefix ne "" ) {

        print FILE <<__EOF__;

            ${prefix}pixel = *$prefix;

__EOF__

    } else {

        print FILE <<__EOF__;

            pixel = *src;

__EOF__

    }

    print FILE <<__EOF__;

            $string

__EOF__

}

sub set_rgba

{

    my $prefix = shift;

    my $format = shift;

    my $string = $set_rgba_string{$format};

    $string =~ s/_/$prefix/g;

    print FILE <<__EOF__;

            $string

            *dst = ${prefix}pixel;

__EOF__

}

sub output_copycore

{

    my $src = shift;

    my $dst = shift;

    my $modulate = shift;

    my $blend = shift;

    my $s = "";

    my $d = "";

    # Nice and easy...

    if ( $src eq $dst && !$modulate && !$blend ) {

        print FILE <<__EOF__;

            *dst = *src;

__EOF__

        return;

    }

    if ( $blend ) {

        get_rgba("src", $src);

        get_rgba("dst", $dst);

        $s = "src";

        $d = "dst";

    } else {

        get_rgba("", $src);

    }

    if ( $modulate ) {

        print FILE <<__EOF__;

            if (flags & SDL_COPY_MODULATE_COLOR) {

                ${s}R = (${s}R * modulateR) / 255;

                ${s}G = (${s}G * modulateG) / 255;

                ${s}B = (${s}B * modulateB) / 255;

            }

            if (flags & SDL_COPY_MODULATE_ALPHA) {

                ${s}A = (${s}A * modulateA) / 255;

            }

__EOF__

    }

    if ( $blend ) {

        print FILE <<__EOF__;

            if (flags & (SDL_COPY_BLEND|SDL_COPY_ADD)) {

                /* This goes away if we ever use premultiplied alpha */

                if (${s}A < 255) {

                    ${s}R = (${s}R * ${s}A) / 255;

                    ${s}G = (${s}G * ${s}A) / 255;

                    ${s}B = (${s}B * ${s}A) / 255;

                }

            }

            switch (flags & (SDL_COPY_MASK|SDL_COPY_BLEND|SDL_COPY_ADD|SDL_COPY_MOD)) {

            case SDL_COPY_MASK:

                if (${s}A) {

                    ${d}R = ${s}R;

                    ${d}G = ${s}G;

                    ${d}B = ${s}B;

                }

                break;

            case SDL_COPY_BLEND:

                ${d}R = ${s}R + ((255 - ${s}A) * ${d}R) / 255;

                ${d}G = ${s}G + ((255 - ${s}A) * ${d}G) / 255;

                ${d}B = ${s}B + ((255 - ${s}A) * ${d}B) / 255;

                break;

            case SDL_COPY_ADD:

                ${d}R = ${s}R + ${d}R; if (${d}R > 255) ${d}R = 255;

                ${d}G = ${s}G + ${d}G; if (${d}G > 255) ${d}G = 255;

                ${d}B = ${s}B + ${d}B; if (${d}B > 255) ${d}B = 255;

                break;

            case SDL_COPY_MOD:

                ${d}R = (${s}R * ${d}R) / 255;

                ${d}G = (${s}G * ${d}G) / 255;

                ${d}B = (${s}B * ${d}B) / 255;

                break;

            }

__EOF__

    }

    if ( $blend ) {

        set_rgba("dst", $dst);

    } else {

        set_rgba("", $dst);

    }

}

sub output_copyfunc

{

    my $src = shift;

    my $dst = shift;

    my $modulate = shift;

    my $blend = shift;

    my $scale = shift;

    output_copyfuncname("static void", $src, $dst, $modulate, $blend, $scale, 1, "\n");

    print FILE <<__EOF__;

{

    const int flags = info->flags;

__EOF__

    if ( $modulate ) {

        print FILE <<__EOF__;

    const Uint32 modulateR = info->r;

    const Uint32 modulateG = info->g;

    const Uint32 modulateB = info->b;

    const Uint32 modulateA = info->a;

__EOF__

    }

    if ( $blend ) {

        print FILE <<__EOF__;

    Uint32 srcpixel;

    Uint32 srcR, srcG, srcB, srcA;

    Uint32 dstpixel;

    Uint32 dstR, dstG, dstB, dstA;

__EOF__

    } elsif ( $modulate || $src ne $dst ) {

        print FILE <<__EOF__;

    Uint32 pixel;

    Uint32 R, G, B, A;

__EOF__

    }

    if ( $scale ) {

        print FILE <<__EOF__;

    int srcy, srcx;

    int posy, posx;

    int incy, incx;

    srcy = 0;

    posy = 0;

    incy = (info->src_h << 16) / info->dst_h;

    incx = (info->src_w << 16) / info->dst_w;

    while (info->dst_h--) {

        $format_type{$src} *src;

        $format_type{$dst} *dst = ($format_type{$dst} *)info->dst;

        int n = info->dst_w;

        srcx = -1;

        posx = 0x10000L;

        while (posy >= 0x10000L) {

            ++srcy;

            posy -= 0x10000L;

        }

        while (n--) {

            if (posx >= 0x10000L) {

                while (posx >= 0x10000L) {

                    ++srcx;

                    posx -= 0x10000L;

                }

                src = ($format_type{$src} *)(info->src + (srcy * info->src_pitch) + (srcx * $format_size{$src}));

__EOF__

        print FILE <<__EOF__;

            }

__EOF__

        output_copycore($src, $dst, $modulate, $blend);

        print FILE <<__EOF__;

            posx += incx;

            ++dst;

        }

        posy += incy;

        info->dst += info->dst_pitch;

    }

__EOF__

    } else {

        print FILE <<__EOF__;

    while (info->dst_h--) {

        $format_type{$src} *src = ($format_type{$src} *)info->src;

        $format_type{$dst} *dst = ($format_type{$dst} *)info->dst;

        int n = info->dst_w;

        while (n--) {

__EOF__

        output_copycore($src, $dst, $modulate, $blend);

        print FILE <<__EOF__;

            ++src;

            ++dst;

        }

        info->src += info->src_pitch;

        info->dst += info->dst_pitch;

    }

__EOF__

    }

    print FILE <<__EOF__;

}

__EOF__

}

sub output_copyfunc_h

{

}

sub output_copyinc

{

    print FILE <<__EOF__;

#include "SDL_video.h"

#include "SDL_blit.h"

#include "SDL_blit_auto.h"

__EOF__

}

sub output_copyfunctable

{

    print FILE <<__EOF__;

SDL_BlitFuncEntry SDL_GeneratedBlitFuncTable[] = {

__EOF__

    for (my $i = 0; $i <= $#src_formats; ++$i) {

        my $src = $src_formats[$i];

        for (my $j = 0; $j <= $#dst_formats; ++$j) {

            my $dst = $dst_formats[$j];

            for (my $modulate = 0; $modulate <= 1; ++$modulate) {

                for (my $blend = 0; $blend <= 1; ++$blend) {

                    for (my $scale = 0; $scale <= 1; ++$scale) {

                        if ( $modulate || $blend || $scale ) {

                            print FILE "    { SDL_PIXELFORMAT_$src, SDL_PIXELFORMAT_$dst, ";

                            my $flags = "";

                            my $flag = "";

                            if ( $modulate ) {

                                $flag = "SDL_COPY_MODULATE_COLOR | SDL_COPY_MODULATE_ALPHA";

                                if ( $flags eq "" ) {

                                    $flags = $flag;

                                } else {

                                    $flags = "$flags | $flag";

                                }

                            }

                            if ( $blend ) {

                                $flag = "SDL_COPY_MASK | SDL_COPY_BLEND | SDL_COPY_ADD | SDL_COPY_MOD";

                                if ( $flags eq "" ) {

                                    $flags = $flag;

                                } else {

                                    $flags = "$flags | $flag";

                                }

                            }

                            if ( $scale ) {

                                $flag = "SDL_COPY_NEAREST";

                                if ( $flags eq "" ) {

                                    $flags = $flag;

                                } else {

                                    $flags = "$flags | $flag";

                                }

                            }

                            if ( $flags eq "" ) {

                                $flags = "0";

                            }

                            print FILE "($flags), SDL_CPU_ANY,";

                            output_copyfuncname("", $src_formats[$i], $dst_formats[$j], $modulate, $blend, $scale, 0, " },\n");

                        }

                    }

                }

            }

        }

    }

    print FILE <<__EOF__;

    { 0, 0, 0, 0, NULL }

};

__EOF__

}

sub output_copyfunc_c

{

    my $src = shift;

    my $dst = shift;

    for (my $modulate = 0; $modulate <= 1; ++$modulate) {

        for (my $blend = 0; $blend <= 1; ++$blend) {

            for (my $scale = 0; $scale <= 1; ++$scale) {

                if ( $modulate || $blend || $scale ) {

                    output_copyfunc($src, $dst, $modulate, $blend, $scale);

                }

            }

        }

    }

}

open_file("SDL_blit_auto.h");

output_copydefs();

for (my $i = 0; $i <= $#src_formats; ++$i) {

    for (my $j = 0; $j <= $#dst_formats; ++$j) {

        output_copyfunc_h($src_formats[$i], $dst_formats[$j]);

    }

}

print FILE "\n";

close_file("SDL_blit_auto.h");

open_file("SDL_blit_auto.c");

output_copyinc();

for (my $i = 0; $i <= $#src_formats; ++$i) {

    for (my $j = 0; $j <= $#dst_formats; ++$j) {

        output_copyfunc_c($src_formats[$i], $dst_formats[$j]);

    }

}

output_copyfunctable();

close_file("SDL_blit_auto.c");